Question: Simplify the following expression: ${3r+7+2+r}$
Explanation: Rewrite the expression to group the ${r}$ terms and numeric terms: $ {3r + r} + {7 + 2}$ Combine the ${r}$ terms: $ {4r} + {7 + 2}$ Combine the numeric terms: $ {4r} + {9}$ The simplified expression is $4r+9$